Sometimes when logging out having had a Plasma desktop session I get
Logout Cancelled by ‘someapp’
The questions is. How do I stop it/ can I stop it doing that. We could get into very deep GDPR
trouble if people think a logout is happening and it doesn’t? ( and they just walk away without
checking as a lot of people do ) . And am in the right place at all i.e. is it a openSUSE issue or
is it a KDE one
Ta
Mal
Ensure that you have closed ‘someapp’ before logging out. (I know kate will cancel logout if there are unsaved edits, I’m afraid I don’t know what other applications are capable of doing it.)
Since there seems to be a lot of programs that can do it there should be a way of just logging out!
What happens is people just click log out and walk away. With Plasma you get a countdown anyway
so logout should mean logout. People expect that to happen. It’s like driving a car and having a
message ‘the application of the brakes was cancelled by …’
You’ll have to take that up with the KDE developers, or more likely the developers of ‘someapp’. I doubt they’ll be willing to change the existing behaviour though.
Personally, I think that closing applications before log-out makes sense, I’ve never really found it a problem.
To use your vehicle analogy, wanting to log out first could be likened to jumping out of the car before it’s stopped 
You (or your Users) also probably need to better describe what your objective is when you Logout.
By definition, a Logout only ends the User session, the machine continues to run. Aside from whether apps running in the logged in User continues to run, the running machine will continue to be exposed to any remote hacking.
If security is your objective, then the User should not just logout if nothing needs to continue to run, the machine should be powered down completely.
If you simply want a workaround to the User session not terminating properly, that’s what the Lockscreen is for.
TSU
Yes, perhaps a better description…
Here is a scenario :-
A teacher goes into a shared teaching room
Then logs on and opens a number of apps
One of these is SIMS ( if you don’t work in a school - it contains all the students details, educational, personal, home issues etc )
The teacher then clicks logout and gets up and leaves the room
//// here is where you say they should have closed all the open apps and check that the logout was successful ////
Maybe because teachers are ‘different’ or they were distracted or they assumed clicking on logout did actually do that
Now app ‘someapp’ cancels the logout but the teacher doesn’t notice or doesn’t check
Next period the room is used by students as a study room or a form room
Suddenly every student gets an A* in every subject, the whole school finds out that student X attempted suicide and then we all go to prison for massive GDPR breach.
Not good
There should be a way that logout means logout even if that means that open files just get dumped
Best wishes
Mal
In most cases changes may not be committed all data must be committed to disk before a log off or shutdown. As the example of kate file not being saved stops the log off. Note this can happen in Windows also if you try to log off or shut down in Windows and some app has unsaved data. If you have saved all data before the log out it should not matter if the program is still running. Uncommitted data should always stop a logout or shutdown.Otherwise you may lose the data and saving or not should always be a human decision It is not having a program open it is having a program open that has data that has not been saved and thus may be lost. Just because you type things in does not mean that the data is safe on the disk. This is computers 101 and all users should know and follow proper procedures.
Also the screen locker will offer protection if set at a reasonable low timeout.
.
If that’s what you really want:
qdbus org.kde.ksmserver /KSMServer logout 0 0 2
Which will force an immediate logout, no questions, no wait … don’t blame me if you lose data or corrupt something though
You could create a launcher to execute it and then add to either the menu or desktop.
(That obviously is for KDE, don’t know if there’s an equivalent for Gnome).
Whilst I agree with you 100% You clearly haven’t worked with teachers
I could write a book on the support calls we have ! We have what we call
the ‘finger of on ness’ as probably a quarter of the calls just need the power
button on something pressing. At night we have to go around and log machines
off. Usain Bolt has nothing on a teacher at 3:30
Best wishes
M
Many thanks. Sadly this is what I do want. All the bad things that could happen are nothing
compared to a student getting access to the SIMS system. I can almost feel you sighing
from here but that’s the world I work in. I will label it ‘Nuclear Logout’ or something like that
Ta
M
Hmm… Sorry. Rather embarrassing, this doesn’t actually force a logout in the manner I thought, an application is still able to cancel it. I misunderstood the documentation.
So I’m afraid it’s probably back to the KDE developers, but as I wrote, I doubt they’ll change that behaviour.
No sweat 
I’ll bug them a bit. Often they are a bit ‘keen’ about doing things
‘the right way’ but they generally have 101 workarounds
Ta
Mal
The point is the program should not normally stop log off unless it is has unsaved data or unfinished processes. If you kill a program with data unsaved you lose data. A program could be designed to auto save on the kill signal I guess but most are not since a human should decide if they want to lose data or save it. So the only real way to fix this is to pre-decide the acceptable save or dump and redesign the used programs to follow that.